Biodiv Sci ›› 2022, Vol. 30 ›› Issue (1): 21407.  DOI: 10.17520/biods.2021407

• Original Papers: Animal Diversity • Previous Articles     Next Articles

Diversity of culturable and in situ bacteria in surface seawater from the central Indian Ocean and the western South China Sea

Chengqiang Xia1,#, Yi Li2,3,#,*(), Yanru Dang3, Qianqian Cha3, Xiaoyan He3, Qilong Qin3   

  1. 1 College of Animal Science, Shanxi Agricultural University, Taigu, Shanxi 030801
    2 College of Life Sciences, Shanxi Agricultural University, Taigu, Shanxi 030801
    3 State Key Laboratory of Microbial Technology, Shandong University, Qingdao, Shandong 266237
  • Received:2021-10-11 Accepted:2021-10-20 Online:2022-01-20 Published:2022-01-29
  • Contact: Yi Li
  • About author:First author contact:

    # Co-first authors


Aims: Bacteria play an important role in driving biogeochemical cycling in the open ocean. Therefore, it is of great significance to investigate the characteristics of marine bacteria and their potential role in the marine environment.

Methods: In this study, surface seawater was collected from 8 sites in the central Indian Ocean and the western South China Sea. Three different media were utilized for strains isolation and identification, and the 16S rRNA gene high-throughput sequencing method was used to analyze the microbial classification and community composition of each study site.

Results: A total of 275 strains, belonging to 4 phyla, 49 genera and 75 species, were isolated and identified. Proteobacteria were the most dominant, accounting for 68.7% of the total isolates, followed by Actinobacteria (21.5%), Bacteroidetes (9.1%) and Firmicutes (0.7%). At the genus level, Microbacterium and Vibrio were the dominant genera, accounting for 30.0% of the total number of isolates. Bacterial abundance and species (89 isolates, 30 genera) in the 1/10 × 2216E medium were the highest among the three kinds of media. Seven, nine and three genera were only found in 2216E, 1/10 × 2216E and glucose-mannose (GM) medium, respectively. Fifty strains (26 species) were identified as potential novel taxa. The sequencing analysis revealed that 23 phyla and 531 genera were found in the surface seawater. Dominant phyla were Proteobacteria (72.2%) and Bacteroidetes (15.3%), dominant genera were Psychrobacter (24.4%), Halomonas (16.3%), and Sulfitobacter (13.9%). In addition, the Shannon-Wiener index and Pielou’s evenness index were significantly higher in the Indian Ocean than the South China Sea (P < 0.05), and bacterial community structure was significantly different between those two regions (P < 0.05).

Conclusion: The results indicated that marine bacteria from the surface seawater of central Indian Ocean and western South China Sea were rich in diversity, and help the most value for further development and research.

Key words: central Indian Ocean, western South China Sea, surface seawater, high throughput sequencing, bacterial diversity